Nguyen Thi Hong Bich, 36, was arrested on Friday while Dong Nai Police launched an investigation into the death of five members in her family, with one other found suffering from cyanide poisoning.

According to police, a 18-year-old man was hospitalised in critical condition on June 26. Doctors said that he suffered from cyanide poisoning.

The man has recovered after receiving treatment. Initial investigation by the police showed that the young man was poisoned by cyanide by his aunt Bich while living in the same house.

At the police station on July 5, Bich admitted that she had bought cyanide to poison her nephew due to conflicts with some members in their family.

Bich's brother told police that five other members in their family had died of the same problems of heart arrhythmia between October 2023 and June 2024. The victims were Bich's father Nguyen Van Hai, her husband whose name is not disclosed, her two children, and a nephew.

According to some neighbours, Bich, her husband and their two children were living in the same house with his brother's family and their father on Hung Vuong Street, Nhon Trach District. They ran a small restaurant at their home.

Police are further investigating the case.